This invention relates to an electrical connector to be mounted on a circuit board in an electrical or electronic appliance, and more particularly to an improved construction for fixing shield plates to a receptacle connector.
In general, an electrical connector comprises a pin connector (for example, refer to numeral 32 in FIG. 1) and a receptacle connector (numeral 74 in FIG. 7). A construction of a hitherto used receptacle connector 74 will be explained by way of example with reference to FIG. 7 which is a perspective view illustrating the conventional receptacle connector 74, a first shield plate 80 and a second shield plate 90. As shown in FIG. 7, the conventional receptacle connector 74 mainly comprises a block 76, contact assemblies 16 and a connecting fixture 20. The contact assembly 16 comprises an insulator 17 made of a plastic material and receptacle contacts 18 made of a metallic material which are fixed in the insulator 17 by press-fitting or by embedding them into the insulator in molding.
The receptacle contact 18 is made as by the known press-working and comprises a connecting portion to be connected to a board, a fixed portion to be fixed to the insulator 17 and a contacting portion to contact the pin contact 36 of a pin connector 32. The insulator 17 is made of an insulating plastic material by the known injection molding or the like.
The connecting fixture 20 is also made of an insulating plastic material by the known injection molding. The connecting fixture 20 holds and fixes thereto the contact assemblies 16 with their protrusions 62 being fitted in latching portions 60 of the connecting fixture 20 (refer to FIG. 2A). The connecting fixture 20 serves to fix the contact assemblies 16 without any misalignment and to make possible to insert all the contact assemblies 16 as a unit into the block 76 by one operation. The contacting fixture 20 has been proposed in Japanese Patent Application No. H10-64,099 filed by the applicant of the present application.
The block 76 will be explained herein. It is also made of an insulating plastic material by the known injection molding. The block 76 is formed with insertion apertures (not shown) into which a required number of the contact assemblies 16 are inserted by press-fitting at one end of the block in the direction of its thickness. The block 76 is further formed in the other end with fitting openings 22 into which pin contacts 36 of the pin connector 32 (refer to FIG. 1) are inserted. On the same side of the fitting openings 22, the block 76 is further provided with a misinsertion preventing groove 24 substantially at the center of its length. A key (not shown) is provided on the pin connector 32 to be fitted into the groove 24 to prevent misalignment insertion of the pin connector 32 into the receptacle connector 74.
Engagement portions 78 are provided on the block 76 at the ends in its width direction (the vertical direction viewed in FIG. 7) near to the fitting opening 22. The engagement portions 78 at one end are adapted to be fitted with a first anchoring pieces 86 of the first shield plate 80, and the engagement portions 78 at the other end adapted to be fitted with a second anchoring pieces 88 of the second shield plate 90. The first and second shield plates 80 and 90 are fitted on the engagement portions 78 in this manner to prevent any floating movement of these shield plates 80 and 90 from the block 76.
A plurality of projections 28 are further provided in a predetermined pitch on the block 76 at the either ends in its width direction (the vertical direction viewed in FIG. 7) on the side of the contact assemblies 16. When the first and second shield plates 80 and 90 are fitted on the receptacle connector 74, these projections 28 are inserted into recesses 48 of the first and second shield plates 80 and 90, thereby ensuring the correct positioning of the first and second shield plates 80 and 90 relative to the receptacle connector 74 with respect to the directions of the width and thickness of the block 76. The projections 28 have a length of the order of 0.8 mm to 1.2 mm, a width of 2 mm to 3 mm and a height of 0.4 mm to 0.5 mm.
The shield plates will be explained hereinafter. First, explaining the first shield plate 80, it has a substantially L-shaped cross-section and includes at its one free end the first anchoring pieces 86 to be fitted on the engagement portions 78 of the block 76 and at the other free end a required number of terminals 84 extending therefrom, which are to be forced into a board (not shown) by press-fitting. At substantially mid position between the adjacent terminals 84, the first shield plate 80 is formed with notches 82 into which are inserted the terminals 84 of the second shield plate 90. The notches 82 serve to fix the first and second shield plates 80 and 90 with each other.
Near to the first anchoring pieces 86, the first shield plate 80 is formed with contacting portions 46 which are bent outwardly so that they can contact pin contacts 36 (refer to FIG. 1) located near to the outer end of the pin connector 32 for grounding. As described above, near to the contacting portions 46 of the first shield plate 80 is provided with the recesses 48 so located and sized that the projections 28 of the block 76 are fitted in the recesses 48. Moreover, the first shield plate 80 is formed with a relief space 56 to facilitate the mounting of the shield plate onto the block 76.
Then, the second shield plate 90 will be explained hereinafter. The second shield plate 90 has a substantially L-shaped cross-section and includes at its one free end the second anchoring pieces 88 to be fitted on the engagement portions 78 of the block 76 and at the other free end a required number of terminals 84 extending therefrom, which are to be forced into a board (not shown) by press-fitting.
After the terminals 84 have been forced into a board by press-fitting, they are fitted in the notches 82 of the first shield plate 80 to achieve the positional alignment of the first and second shield plates 80 and 90. Near to the second anchoring portions 88, the second shield plate 90 is formed with contacting portions 46 which are bent outwardly so that they can contact pin contacts 36 (refer to FIG. 1) located near to the outer end of the pin connector 32 for grounding. As described above, near to the contacting portions 46 of the second shield plate 90 is provided with the recesses 48 so located and sized that the projections 28 of the block 76 are fitted in the recesses 48. The second shield plate 90 is formed with a relief space 56 for the same purpose in the first shield plate 80.
Finally, the process for assembling the receptacle connector 74 of the prior art will be explained. First, the receptacle contacts 18 are fixed to the insulator 17 by press-fitting, or embedding them in the insulator by molding or the like. The thus formed contact assemblies 16 including the receptacle contacts 18 are mounted on the connecting fixture 20 and the contact assemblies 16 in this condition are press-fitted and fixed into the insertion apertures of the block 76.
Usually, the blocks 76 having the contact assemblies 16 fixed thereto and the shield plates 80 and 90 are separately sent to customers, who, after received these products, may set them on boards. There are two methods for setting these products on boards. In the first method, the receptacle connector 74 and the first shield plate 80 with its first anchoring pieces 86 engaging the engagement portions 78 of the block 76 are simultaneously forced into the board by press-fitting, and thereafter the second anchoring pieces 88 of the second shield plate 90 are brought into engagement with the engagement portions 78 of the block 76 and the second shield plate 90 is forced into the board by press-fitting from the opposite side of the shield plate 80.
In the second method, first the receptacle connector 74 is forced into a board by press-fitting, and thereafter the first anchoring pieces 86 of the first shield plate 80 are engaged with the engagement portions 78 of the block 76 and the first shield plate 80 is forced into the board by press-fitting. Thereafter, the second anchoring pieces 88 of the second shield plate 90 are brought into engagement with the engagement portions 78 of the block 76 and the second shield plate 90 is forced into the board by press-fitting from the opposite side of the shield plate 80.
As described above, the first and second shield plates 80 and 90 are mounted on the block 76 only by hanging their first and second anchoring pieces 86 and 88 on the engagement portions 78 of the block 76 of the receptacle connector 74, so that there is a tendency of the first and second shield plates 80 and 90 to move away from the block 76. As a result, when the pin connector 32 and the receptacle connector 74 are connected to each other, the first and second shield plates 80 and 90 of the receptacle connector 74 are accidentally deformed and even the pin contacts 36 of the pin connector 32 may be damaged. This is a problem to be solved in the prior art.
Such deformations of the pin contacts 36 and first and second shield plates 80 and 90 will cause need for replacement of the board and the pin connector 32 and receptacle connector 74 themselves, with resultant increase of cost. Moreover, as the receptacle connectors 74 and the first shield plates 80 in separated condition are send to customers, the man-hours for the control or management of the respective parts will be increased to increase the cost.
In the case that the receptacle connector 74 and the first shield plate 80 are separately forced into the board by press-fitting according to the customer's method as described above, the press-fitting operation must be effected two times on the same side of the board so that particular jigs must be required for the respective press-fittings and the man-hours for assembling will be increased, resulting in the increase of cost. What is worse still, the second shield plate 90 is forced into the board by press-fitting from the opposite side of the first shield plate 80 so that an exclusive jig is required accompanying a troublesome operation to increase the cost.